Telecom technologies are developing constantly. As the next generation network (NGN) framework comes into existence, the ways of providing telecom services are changing, and various new services are emerging. The softswitch-based IP Centrex service and intelligent network (IN) service are emerging in response to the service requirements.
The IP Centrex service is an IP-based Centrex service. It is a value-added service that combines the flexibility of IP networks and the Centrex service on fixed networks, and provides users with functions such as intra-group call, non intra-group call, outgoing call screening, short number dialing, and attendant transfer. The following describes the method for implementing the IP Centrex service. When user A calls user B, after the softswitch domain of user A receives a call request from user A, the softswitch domain of user A forwards the call request to a corresponding application server (AS). Then, the AS accesses the service data of user B, and sends the call request of user A to the softswitch domain of user B to perform the subsequent call connection. During the preceding implementation of the IP Centrex service, if the call request is for an intra-group call, the AS that executes the IP Centrex service performs discount charging, and then performs the subsequent call connection; if the call request is for a non intra-group call, the AS that executes the IP Centrex service directly performs the subsequent call connection.
The IN service is a series of emerging services based on the intelligent network, and can implement functions such as incoming call screening, voice control, prepaid charging, and mobile virtual private network (VPN). The IN service is diversified, flexible, cost-effective, and fast, and is very popular among a large number of users. The IN service may be implemented in the following three different methods: 1. A softswitch accesses a service control point (SCP) on a conventional intelligent network; 2. A service switching point (SSP) on a conventional intelligent network accesses an AS; 3. A third party provides various IN services. The following describes the first method for implementing the IN service. In this method, the softswitch implements the service switching function (SSF), triggers the IN service, and interworks with the SCP on the conventional intelligent network through a signaling gateway; the softswitch accepts the IN call control performed by the SCP, connects the call, and interacts with users to provide the users with various IN services. It is widely known that the IN service can implement intra-group call and non intra-group call services.
With the growth of user requirements, a user may tend to subscribe to the IP Centrex service and the IN service at the same time. However, conflicts may occur when the user subscribes to both the IP Centrex service and the IN service. If the IN service is triggered, the IP Centrex service cannot be implemented, and thus the discount charging cannot be performed on the intra-group call.